Thermal processing system and methods for forming low-k dielectric films suitable for incorporation into microelectronic devices

ABSTRACT

Single wafer processing methods and systems for manufacturing films having low-k properties and low indices of refraction. The methods incorporate a processing station in which both curing and post-cure, in situ gas cooling take place.

RELATED CASES

[0001] This application is a divisional of U.S. Ser. No. 09/903,114,filed Jul. 11, 2001, entitled “THERMAL PROCESSING SYSTEM AND METHODS FORFORMING LOW-K DIELECTRIC FILMS SUITABLE FOR INCORPORATION INTOMICROELECTRONIC DEVICES,” which claims the benefit of U.S. ProvisionalApplication Serial No. 60/325,784, filed Jul. 12, 2000, entitled“THERMAL PROCESSING SYSTEM AND METHODS FOR FORMING LOW-K DIELECTRICFILMS SUITABLE FOR INCORPORATION INTO MICROELECTRONIC DEVICES,” whichapplications are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

[0002] The present invention relates to systems and methods for formingdielectric films suitable for microelectronic applications, e.g., foruse in forming microelectronic interconnect structures in logic andmemory devices. In particular, the present invention is directed tointegrated systems and methods in which such films are formed on amicroelectronic substrate by thermally curing a dielectric precursor ina process chamber and then cooling the cured material in situ before thesubstrate is removed from the chamber.

BACKGROUND OF THE INVENTION

[0003] As the operating frequencies of electronic devices enter thegigahertz range and as the dimensions of device features become smaller,insulating materials with low dielectric constants (low-k dielectricmaterials) are needed to achieve reasonable power consumption, to reducesignal delay, and to minimize interconnect crosstalk in high performanceULSI circuits. Materials with low dielectric constants are stronglydesired in many microelectronic device applications, including both gapfilling and Damascene applications. The dielectric constant of adielectric material is one property indicative of its quality. Othercharacteristics indicative of the quality of a dielectric materialinclude mechanical properties, index of refraction, uniformity, thermalstability, manufacturability, integration with Cu or Al and the like.

[0004] Most dielectric films are formed using either a spin coatingapproach, or a chemical vapor deposition approach, e.g., PECVD or HDP.In the spin coating approach, a spin coatable solution containing adielectric film precursor (usually one or more curable monomers,oligomers, and/or polymers) dissolved in a suitable solvent is spincoated onto a rotating substrate, such as a microelectronic deviceprecursor (e.g., a silicon wafer) or the like, to form a uniform,relatively thin film coating on the substrate. The coated substrate isthen baked at a temperature typically in the range of 100° C. to about325° C. in order to remove the solvent, dry the coating, and advance thedielectric material to the B-stage of polymerization. The coating isthen cured, i.e., advanced to the C-stage of polymerization, by heatingthe substrate at a suitable curing temperature typically in the range ofabout 350° C. to about 450° C.

[0005] The cured dielectric films are generally collectively referred toas low-k spin on dielectric materials. A variety of low-k spin ondielectric precursor materials are commercially available from a numberof different vendors and are sold for the purpose of forming dielectricfilms in microelectronic devices. Representative examples of suchproducts are available under the trade designations FLARE fromHoneywell, Inc., SILK from Dow Chemical Co., VALOX from Schumacher, HOSPfrom Honeywell, Inc., and HSQ from Dow Coming Company. The FLARE andSILK materials are organic, being poly(arylene) ethers and aromatic,respectively. The HOSP material is inorganic-organic, being amethyl-substituted silsesquioxane. The HSQ material is inorganic, beinga hydrogen silsesquioxane. Each of these materials requires uniqueprocessing steps for successful integration with multilevel aluminumand/or copper in Dual Damscene processing, although each generally isthermally cured at temperatures in the range from about 350° C. to about450° C.

[0006] Dielectric precursor materials that form porous dielectric films(preferably ultra low-k and extreme low-k films) upon curing are alsoknown. Generally, these materials include not only a curable dielectricprecursor but also one or more relatively volatile components (referredto as “porogens”). These porogens tend to outgas during curing,contributing to the film porosity. Representative examples of suchmaterials are known the respective trade designations NAUTILUS™ from theDow Chemical Co., POROUS FLARE™ from Honeywell, Inc., POLY ELK™ and MONOELK™ from Schumacher (Carlsbad, Calif.), LKD™ from JSR Corp., ISP™ fromCatalysts and Chemicals, Ltd., Japan, and HSG™ from Hitachi ChemicalCo., Ltd.

[0007] The manner in which a low-k spin on dielectric material is curedhas a significant impact upon the quality of the resultant dielectricfilm. If curing is carried out carelessly, the film quality will suffer.In some instances, the film quality may be too poor to use as a blanketfilm and/or may not be able to withstand aluminum or copper integrationprocesses. Factors affecting the cure include how the time, temperature,and processing environment are controlled during the cure process.

[0008] Conventionally, the coating and baking steps have been carriedout in an integrated fashion in the same tool. However, curing typicallyhas been accomplished by heating a batch of coated microelectronicsubstrates in a stand-alone furnace. Furnaces have been favored becauseconventional wisdom has the view that heated platen curing cannotproduce dielectric films of the quality demanded by the microelectronicindustry.

[0009] Yet, furnace processing is not the optimum approach from theperspective of the present inventors. Furnace curing tends to be a batchprocess in which as many as 30 to 100 wafers or more are cured at thesame time, yet manufacturers desire single wafer processing to helpensure that each and every in-process wafer is processed under the sameconditions. Single wafer processing is also desirable in the event thata process error occurs, because only a single substrate is at risk. Incontrast, if a process error occurs during a furnace cure, the entirebatch of substrates could be ruined. Given that a single in-process 300mm wafer can be worth up to $1 million or more, minimizing process riskis an important concern.

[0010] In the course of developing the present invention, we also haveobserved that furnace processing inevitably leads to some nonuniformityand quality problems when making dielectric films. These nonuniformityand quality problems occur, in our view, at least in part because thetime period between the bake and cure steps varies too much fromsubstrate to substrate. Generally, those substrates that are bakedearlier must wait until later substrates are baked before the entirebatch is submitted to the furnace. Indeed, the time between the bake andcure has been inadequately controlled in conventional processes. Otherinterstation and intrastation time periods also have not been adequatelycontrolled. Examples from conventional processes are the delay betweenthe coat and bake steps as well as the delay between the curing step andthe subsequent cooling step. We have discovered that these kinds of timevariations can adversely affect film quality and uniformity from lot tolot, and even from substrate to substrate. Additionally, unlike compact,space efficient heated platens, furnaces tend to be rather large,standalone units that occupy valuable cleanroom floorspace.

[0011] Accordingly, there remains a strong need for improved ways tomanufacture lower k dielectric films, particularly by using a singlewafer processing approach to minimize the risk that process deviationswill adversely affect more than one wafer. There also remains a desireto effectively use heated platen curing of low-k spin on dielectricmaterials.

SUMMARY OF THE INVENTION

[0012] The present invention provides improved, single wafer processingmethods and systems for manufacturing films having low-k properties andlow indices of refraction. Low-k spin on dielectric films of the presentinvention are also characterized by exceptional levels of uniformity,thermal stability, and mechanical properties. Importantly, thesecharacteristics are achieved with high throughput, e.g., up to about 100substrates per hour per 64 ft² of cleanroom floor space. Additionally,both 200 mm and 300 mm wafers can be processed in the same tool inpreferred embodiments.

[0013] The present invention is based upon several innovations thatsingly and in combination help to provide these advantages. Firstly, ithas been found that controlling the time periods between one or more ofcoating, baking, curing, and/or cooling steps can greatly enhance thethroughput, uniformity, and quality of low-k dielectric films. Suchuniformity allows substrates to be sequentially processed, parallelprocessed, or custom processed on demand using one or more processrecipes with the confidence that films made in accordance with aparticular recipe will be substantially identical to each other withlittle if any variation in process signature imparted to the films.

[0014] Additionally, low-k spin on dielectric quality and uniformityalso are greatly enhanced by integrating the coating, baking, curing,and cooling functions into a single, integrated processing system. Suchintegration makes it possible to control the consistency and timing ofevery process step carried out in the course of forming dielectricfilms. A particular process recipe may be carried out from substrate tosubstrate or lot to lot with very little detectable variation ascompared to conventional furnace processing.

[0015] Another feature of the present invention that helps to providehigh quality dielectric films is an innovative processing station inwhich both curing and post-cure, in situ cooling take place. Thisintegration of curing and cooling into the same process stationvirtually eliminates any kind of variation, including time variation, inthe curing and cooling process. This is quite advantageous given thatthe curing step of dielectric film formation tends to be the mostimportant step in the process. The integration of curing and coolinginto a single process station also allows oxygen exposure to beaccurately controlled at all times when the low-k spin on dielectricfilm is hot enough to be susceptible to thermal oxidation damage. Incontrast to circumstances when a robot handles a very hot device bearinga dielectric film, in situ cooling also minimizes the robot's signatureimparted to the cooled device when the device is removed from thestation by the robot.

[0016] The present invention also involves an innovative architecturefor the integrated curing/in situ cooling station that allows a simpleheated platen, instead of a furnace, to be used in production forthermal curing. Because a heated platen is relatively compact, unlike afurnace, the ability to use a heated platen allows the station to beintegrated into the same cluster tool as the coating and bakingstations. This, in turn, further facilitates forming dielectric filmswith consistency with very little variation in individual process stepsfrom substrate to substrate and lot to lot.

[0017] Many features of the innovative architecture help to make heatedplaten curing of low-k spin on dielectric materials a reality forproduction and/or research and development purposes. These innovativefeatures include but are not limited to the following:

[0018] (a) an innovative lid design with multiple plenums to allow gasflow dynamics in the chamber to be carefully controlled;

[0019] (b) a side door design to minimize exposure to the ambient duringloading and unloading of in-process microelectronic substrates;

[0020] (c) a hollow base supporting the heated platen to help thermallyisolate the heated platen from its housing;

[0021] (d) a double-walled housing to enhance thermal isolation of theheated platen and processing chamber from the ambient;

[0022] (e) a cooled seal between the heated platen utility conduit andthe housing to allow polymeric seals to be used that might otherwise bedamaged by the high temperatures encountered in spin on dielectriccuring;

[0023] (f) the capability for controlling the oxygen content in theprocess chamber during any desired portion of the curing and coolingstages of operation;

[0024] (g) the capability to establish a vacuum in the process chamberwhen handling materials such as porous spin on dielectric materials; and

[0025] (h) the capability to cool the device in situ with a gas.

[0026] In one aspect, the present invention relates to a method offorming a cured, dielectric composition on a substrate, comprising thesteps of:

[0027] (a) coating a composition comprising a thermally curable,dielectric precursor onto at least a portion of the substrate;

[0028] (b) causing the coated substrate to be positioned in a processchamber;

[0029] (c) while the coated substrate is positioned in the processchamber:

[0030] (i) thermally curing the dielectric precursor to form the cureddielectric composition; and

[0031] (ii) causing a gas to coolingly contact the cured dielectriccomposition; and

[0032] (d) after said gas coolingly contacts the cured dielectriccomposition, removing the coated substrate from the process chamber.

[0033] In another aspect, the present invention relates to a method offorming dielectric compositions on a plurality of substrates, comprisingthe steps of:

[0034] (a) coating a composition comprising a curable dielectricprecursor onto a first substrate;

[0035] (b) causing the coated substrate to be prebaked, said prebakingbeing initiated after a first time interval from the end of the coatingstep;

[0036] (c) causing the coated substrate to be thermally cured, saidthermal curing being initiated after a second time interval from the endof the pre-baking step;

[0037] (d) causing the thermally cured substrate to be cooled, saidcooling being initiated after a third time interval from the end of thethermal curing step; and

[0038] (e) repeating steps (a) through (d) for at least one additionalsubstrate, wherein the respective second time intervals for each of thefirst coated substrate and the at least one additional coated substrateare substantially the same.

[0039] In another aspect, the present invention relates to a method offorming a cured, dielectric composition on a substrate. A compositioncomprising a thermally curable, dielectric precursor and an amount ofsolvent such that the composition has a coatable viscosity is coatedonto at least a portion of the substrate. The coated substrate ispre-baked at a first, relatively low temperature profile underconditions such that at least a portion of the coated dielectricprecursor is uncured and the coated composition comprises a residualamount of solvent. The dielectric precursor is thermally cured at asecond, relatively high temperature profile under conditions such thatat least substantially all of the dielectric precursor is cured to formthe dielectric composition. The cured dielectric composition is thencooled.

[0040] In another aspect, the present invention relates to a method offorming a cured, dielectric composition on a substrate. A compositioncomprising a thermally curable, dielectric precursor is coated onto atleast a portion of the substrate. The coated substrate is caused to bepositioned in a process chamber. While coated substrate is caused ispositioned in the process chamber, the dielectric precursor is thermallycured to form the cured dielectric composition, wherein at least aportion of the thermal curing occurs under anaerobic conditions; and agas is caused to coolingly contact the cured dielectric composition.After the gas coolingly contacts the cured dielectric composition, thecoated substrate is removed from the process chamber.

[0041] In another aspect, the present invention relates to a method offorming respective dielectric compositions on a plurality of substrates,comprising the steps of:

[0042] (a) causing a first composition comprising a first dielectricprecursor to be coated onto a first substrate;

[0043] (b) causing the coated, first substrate to be positioned in aprocessing chamber;

[0044] (c) while the first substrate is positioned in the processingchamber:

[0045] (i) causing the first substrate to be in thermal contact with aheat source under conditions effective to thermally cure the first,coated substrate; and

[0046] (ii) causing a gas to coolingly contact the thermally cured,first substrate; and

[0047] (d) repeating steps (a) through (c) for a second substrate.

[0048] In another aspect, the present invention provides a method offorming respective dielectric compositions on a plurality of substrates,comprising the steps of:

[0049] (a) providing first and second groups of substrates, each of saidgroups comprising at least one substrate to be processed;

[0050] (b) in accordance with a first process recipe:

[0051] causing a first composition comprising a first dielectricprecursor to be coated onto each substrate in the first substrate group;

[0052] causing each of the coated, substrates of the first group to bepositioned in a processing chamber;

[0053] while each of the substrates of the first group is positioned inthe processing chamber: causing each such coated substrate of the firstgroup to be in thermal contact with a heat source under conditionseffective to thermally cure such coated substrate; and causing a gas tocoolingly contact each of the thermally cured, first substrates; and

[0054] (c) in accordance with a second process recipe different than thefirst process recipe, repeating step (b) for each of the substrates inthe second group.

[0055] In another aspect, the present invention relates to an apparatusfor thermally processing a microelectronic device precursor. Theapparatus includes a process chamber in which the precursor ispositioned during processing. A heat is source thermally coupled to theprocess chamber in a manner such that the precursor may be heated duringprocessing. A source of a cooling gas is in fluid communication with theprocess chamber such that the cooling gas may be caused to coolinglycontact the precursor during processing. A control system controls theheat source and source of cooling gas in order to subject the precursorto a desired thermal processing profile involving at least one heatingstep and at least one cooling step during processing.

[0056] In another aspect, the present invention provides a cluster tool,comprising at least one combination heat/cool process station. Thestation includes a process chamber in which the precursor is positionedduring processing. A heat source is thermally coupled to the processchamber in a manner such that the precursor may be heated duringprocessing. A source of a cooling gas is in fluid communication with theprocess chamber such that the cooling gas may be caused to coolinglycontact the precursor during processing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The above-mentioned and other advantages of the presentinvention, and the manner of attaining them, will become more apparentand the invention itself will be better understood by reference to thefollowing description of the preferred embodiments of the inventiontaken in conjunction with the accompanying drawings, wherein:

[0058]FIG. 1 is a partially exploded view in perspective of anintegrated curing and in situ cooling apparatus of the presentinvention.

[0059]FIG. 2 is a cross-sectional view of the processing chamber of theapparatus shown in FIG. 1.

[0060]FIG. 3 is an exploded perspective view of the lid used in theapparatus of FIG. 1.

[0061]FIG. 4 is a schematic plan view of the heated platen and itsheating element that are used in the apparatus of FIG. 1.

[0062]FIG. 5 is a schematic representation showing a system forcontrolling the level of oxygen during operation of the apparatus ofFIG. 1.

[0063]FIG. 6 is a schematic plan view of a tool cluster of the presentinvention suitable for production.

[0064]FIG. 7 is a schematic plan view of a tool cluster of the presentinvention suitable for research and development.

[0065]FIG. 8 is a flow chart of one mode of operation of the toolcluster of FIG. 6 for making a low-k spin on dielectric film on asubstrate.

[0066]FIG. 9 is a flow chart of another mode of operation of the toolcluster of FIG. 6 in which low-k spin on dielectric films are formed inparallel fashion.

DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS

[0067] The principles of the present invention are advantageouslypracticed in connection with innovative processing stations in whichlow-k spin on dielectric materials may be both cured and then cooled insitu with a gas. Representative embodiments of such processing stationsare described in Assignee's copending U.S. patent application titled“Thermal Processing Chamber for Heating and Cooling Wafer-like Objects”,having U.S. Ser. No. 09/351,586, filed Jul. 12, 1999, in the names ofWomack et al., the entirety of which is incorporated herein byreference. Another particularly preferred embodiment of such aprocessing station is identified by the trade designation “INSTACURE”and is commercially available as a modular component of the CALYPSO™cluster tool from FSI International, Inc., Fremont, Calif.

[0068] The INSTACURE processing station is generally identical to theprocessing stations described in Assignee's copending applicationidentified above with five general exceptions. First, the chamber andbakeplate of the INSTACURE processing station are sized to handledevices having a range of sizes, including both 200 mm and 300 mmsemiconductor wafers. Second, the bakeplate included in the INSTACUREprocessing station includes separately controllable, inner and outerheating zones. Third, the lid design of the INSTACURE processing stationis modified to introduce process gas(es) into the processing chamberthrough a showerhead design including a plurality of gas ports of innerand outer lid plenums. Fourth, the cooling and exhaust structure at thebase of the bakeplate support members of the INSTACURE processingstation is more compact and effective. Fifth, the bottom of the housingof the INSTACURE processing station is double walled to further improvethe thermal insulation properties of the housing.

[0069] These five modifications are illustrated in FIGS. 1 through 4where a representative embodiment of the modular “INSTACURE” processingstation 10 is shown. To the extent that the components and constructionof processing station 10 is similar to that of the thermal processingstation shown in FIGS. 1 through 6 of Assignee's co-pending applicationidentified above, their description and functionality will be identifiedbut not described in detail again herein. However, the followingdescription will include a more detailed explanation of the fivedifferences noted herein as well as a detailed explanation of apreferred mode of operation. It is further understood that any of suchdifferences may be incorporated into a processing station of the presentinvention independently or in any combination with one another.

[0070] With reference to FIGS. 1 through 4, an apparatus is illustratedincluding processing station 10 supported upon support plate 12 thatfacilitates modular mounting of station 10 into a modular cabinet of theCALYPSO™ cluster tool. Although advantageously used as a station is suchcluster tool, station 10 may be provided as a stand-alone system whereinthe station 10 and optionally support plate 12 are supported and encasedin a suitable housing (not shown). Protective heat shield 15 fits overstation 10 to help prevent an operator from accidentally touchingstation 10 when station 10 is hot.

[0071] Station 10 is shown as being cylindrical to accommodate circularsemiconductor wafers, but need not be. Preferably, station 10 compriseshousing 11 formed from a double-panel bottom wall 20, a double-panelcylindrical side wall 22, and a double-panel lid 24. The preferreddouble panel structure of these housing components helps to thermallyisolate processing chamber 14 from the ambient.

[0072] The components of station 10 may be formed from any suitabletemperature-resistant material including metals, ceramics, combinationsof these, and the like. Preferably, components of station 10 are formedfrom metal materials, such as aluminum, aluminum alloys, stainlesssteel, combinations thereof, and the like. It is further preferable thateach of the components to be welded to one another be of similar metalsto facilitate such welding. The result is a thermally and mechanicallyrobust structure. Of course, for other applications, other materials maybe suitable and other connection techniques may be utilized. Forexample, polymeric materials may be usable and adhesives may connect thecomponents for processes carried out at sufficiently low processingtemperatures.

[0073] A transfer slot 26 is provided through a portion of side wall 22so as to provide access to and from processing chamber 14. Preferably,the transfer slot 26 is sized and shaped to accommodate a roboticmechanism (not shown) that is usable for loading and unloading substrate(not shown) from processing chamber 14. However, the transfer slotpreferably is not too much larger than is needed for such access so asto prevent excessive exposure to the ambient when transfer slot 26 isopen. For example, it is often desirable to provide a controlled,anaerobic environment within processing chamber 14. In thiscircumstance, a minimized transfer slot size is beneficial in preventingunwanted oxygen in the ambient from entering the internal processingchamber 14.

[0074] The transfer slot 26 is also preferably sealingly closable by achamber door 28 that is moveable through a range of motion includingopened and closed positions by a door closure mechanism 30. Preferably,door 28 is biased towards a closed position in the absence of anactuating, opening force. Chamber door 28 opens towards the outside ofstation 10 and, when closed, seats against housing adapter 29 thatprovides a suitable surface to closingly engage door 28. Housing adapter29 may be fabricated in any conventional way without compromising thesealable nature of the internal processing chamber 14. Housing adapter29 is shown as a separate part that is attached to the exterior ofstation 10, but could be integral with housing 11 of station 10 ifdesired.

[0075] Door closure mechanism 30 controls the opening and closing ofdoor 28. The door closure mechanism 30 can comprise any known ordeveloped mechanism for opening and closing the chamber door 28, butpreferably such door closure mechanism 30 not only moves the chamberdoor 28 between opened and closed positions (i.e., to and from aposition in front of the transfer slot 26) but also is capable of urgingthe door 28 toward chamber side wall 22 when the chamber door 28 ispositioned in a closed position in front of the transfer slot 26. Withthe addition of a seal 32 provided within a perimetric groove on theinside surface 33 of the chamber door 28, such a door closure mechanism30 assures a proper sealing of the internal processing chamber 14.

[0076] To further facilitate this sealing arrangement, a perimetricflange 34 is also preferably secured to side wall 22 around the transferslot 26 to provide an outer perimetric sealing surface 35 that seal 32engages in the closed position of the chamber door 28. Alternatively,other closure mechanisms that include pneumatic, hydraulic, mechanicaland electromechanical drive substrates may instead by used. It ispreferable, however, that the chamber door 28 be movable not onlybetween positions opening and closing the transfer slot 26, but alsomovable toward and away from the side wall 22 to provide a good sealingarrangement. Such movements can be imparted by one or more independentdrive mechanisms.

[0077] In accordance with one aspect of the present invention, the sidewall 22 preferably has a multi-wall structure (i.e. having two or morespaced walls). In accordance with the embodiment illustrated in FIGS. 1through 4, for example, the side wall 22 includes a radially extendingannular top portion 36, a radially extending annular middle portion 38,and a radially extending annular bottom portion 40. An outer wall 42 isfurther provided and connected to the annular top, middle and bottomportions 36, 38 and 40, respectively, to define the double-wallstructure. The outer wall 42 may comprise an upper wall portion 44 and alower wall portion 46 that may be fabricated independently or as asingle, integrated part. In this regard, the middle annular portion 38may extend all the way around the side wall 22, or may extend as aplurality of discrete, projecting posts or the like arranged about theside wall 22. Alternatively, the middle annular portion 38 may beeliminated, but its presence is preferred to help provide mechanicalstructural strength to the double wall structure.

[0078] In any case, the double wall structure defines one or moreinternal wall cavities that, as illustrated, are divided into an upperwall cavity 48 and a lower wall cavity 50. The upper wall cavity 48 doesnot extend completely around the internal processing chamber 14 as theperimetric flange 34 defining the transfer slot 26 blocks it at oneportion of the side wall 22. The lower wall cavity 50 preferably extendscompletely about the internal processing chamber 14. The outer wall 42is preferably connected with the inner wall 22, and the perimetricflange 34 is preferably connected with the side wall 22 by welding,although any suitable attachment technique may be used.

[0079] The chamber's bottom wall 20 is preferably fabricated intregallywith the side wall 22. However, it may otherwise be formed separatelyand structurally secured to the side wall 22 by any conventional meanssuch as by welding. In this embodiment, the bottom wall 20 comprises adouble wall structure including inner wall member 21 and outer panels 23that are attached to ribs 25 so as to be spaced apart from inner wallmember 21. Cavities 27 are defined by the spaced apart structure. Bottomwall 20 includes an opening 52, preferably centrally located, tofacilitate the passage of components to and from the heated platen 18through heated platen post 94.

[0080] Heated platen 18 is positioned in processing chamber 14 ofstation 10 and generates heat that is transferred to an in-processmicroelectronic substrate (not shown) when the substrate and the heatedplaten are in thermal contact with each other. As described below inconnection with a discussion of a preferred mode of operation of station10, thermal contact does not necessarily mean that the substrate andsurface 90 are in direct physical contact, and indeed preferably meansthat there is a small gap between surface 90 and the substrate acrosswhich thermal heat transfer may still occur. For steady state operation,heated platen 18 is typically maintained at a temperature effective tocure the particular type of spin on dielectric material being used. Thistemperature typically is in the range of from about 350° C. to about450° C.

[0081] Heated platen 18 preferably comprises a heating mechanism forproviding heat transfer to the substrate. A preferred heating mechanismis shown in FIG. 4. The preferred heating mechanism includes a pair ofspiral, electroresistive heating elements 130 and 131 that are embeddedin hotplate 18. Elements 130 and 131 each uniformly traverse respectiveinner and outer heating zones to allow the temperature in each zone tobe independently controlled. The use of multiple heating zones in thisfashion makes it easier to establish and maintain a uniform temperatureacross the entirety of surface 90.

[0082] Other heating mechanisms may be used if desired. For example,assignee's copending application identified above shows a heated platenin which a single heating cable is embedded in the heated platen in auniform spiral. Instead of heating cables, film heaters may also beused, such as the type including a film layer or mica layer having aheater circuit printed on a surface thereof. Such a film heater could beformed on surface 90. As yet another alternative, one or more heatercircuits may be printed directly onto the top, within via printing ontosubsequently laminated layers, or onto bottom surface of heated platen18. As yet another alternative, the heating substrate disclosed incopending U.S. patent application Ser. No. 09/035,628, filed Mar. 5,1998, and owned by the assignee of the subject application, could alsobe utilized. As still another option, heated platen 18 may include oneor more internal passages through which a hot process fluid flows inorder to provide the desired heat output.

[0083] Heated platen 18 is supported, at least in part, upon hollowpedestal base 54. Hollow pedestal base 54 sits within an annular recess56 formed within the bottom wall 20 on the internal chamber side.Conventional bolts 58 can secure the pedestal base 54 to the bottom wall20. The hollow character of pedestal base 54 helps to thermally isolateheated platen 18 from bottom wall 20. To effectively seal the internalprocessing chamber 14, a seal ring 60 is provided between a lowersurface 62 of the pedestal base 54 and the bottom of the annular recess56 so that as the pedestal base 54 is mounted via the bolts 58, a goodsealing relationship is established. To facilitate this construction,the central portion 64 of the bottom wall 20 is preferably made thicker.

[0084] Also in the thicker central portion 64 of bottom wall 20, anexhaust passage 66 is positioned and provides a pathway for removal ofprocess fluids from processing chamber 14. Exhaust channel 66 ispreferably annular as provided by an annual recess of the centralportion 64 that is open to the internal chamber side thereof. One ormore passages (not shown) are also provided extending through theremainder of the thickness of the central portion 64 so that exhaustfluids can be withdrawn from the exhaust channel 66 to the outside ofstation 10 by conventional tubing and fittings or the like. To modulatethe size of the inlet passages leading into the exhaust channel 66 fromchamber 14, a removable exhaust plate 70 is provided having anarrangement of orifices 72 arranged along the exhaust plate 70 in anydesired pattern and total open area. Thus, by fluidly connecting theexhaust channel 66 to an exhaust system, e.g., a vacuum, fluid can bewithdrawn from the processing chamber 14 through the orifices 72 intothe exhaust channel 66 and out of the station 10. By using a removableexhaust plate 70, the size, pattern, an arrangement of the orifices 72can easily be varied depending on any particular application of thestation 10 by merely replacing the exhaust plate 70 with another havingorifices of a different size and/or pattern. The exhaust plate 70 ispreferably fitted within a stepped portion of the annular recess 68 andis preferably secured in place by overlapping portions of pedestal base54.

[0085] Also provided within the central portion 64 of the bottom wall20, is a cooling channel 78 for circulating a cooling fluid, e.g., a gasor liquid, to help cool seal 60. The cooling channel 78 preferablycomprises a recess formed in the central portion 64 of bottom wall 20.The recess is open to the outside of the bottom wall 20. The coolingchannel 78 preferably substantially forms a circular channel (as viewedin a plan view) that is thermally proximal to seal ring 60, butpreferably stops short of defining a full circle so that one end of thecooling channel 78 can be utilized as an inlet and its other end can beused as an outlet. To close the cooling channel 78 from the outside, aplate 80 is secured to the central portion 64 of the bottom wall 20 soas to sealingly cover the cooling channel 78 and to provide inlet andoutlet passages (not shown) by which the cooling channel 78 can beappropriately fluidly connected with input and outlet lines of a coolingsystem in any conventional way.

[0086] Also provided through the central portion 64 of the bottom wall20 are a number of (preferably three) passages 82 (only one shown inFIG. 2) that accommodate reciprocal movement of lift pin mechanisms 84.In addition to facilitating the reciprocal movement of the lift pinmechanisms 84, the passages 82 must permit this movement whileeffectively sealing the internal processing chamber 14 from the ambient.To do this, seal rings 86 are preferably installed within a recessprovided from the outside of the central portion 64 around the passages82 for providing sealing sliding engagement with the lift pin mechanisms84. Such seal rings 86 may be secured in place by mounting platesretained, in turn, by a plurality of fasteners or any other conventionalmeans.

[0087] The passages 82, and thus the lift pin mechanisms 84, arepreferably arranged concentrically (but need not be) about the opening52. Lift pins extend through passages 88 (only one shown in FIG. 2)that, in turn, extend entirely through the thickness of heated platen18. Heated platen 18, which is directly supported by the pedestal base54, provides a support surface 90 that can be positioned in thermaltransfer contact with an in-process microelectronic substrate (notshown). The lift pin mechanisms 84 are movable from a position wheretheir tips 85 place the substrate into thermal transfer contact.

[0088] Lift pin mechanisms 84 also are movable as driven by a reciprocaldrive mechanism (not shown) to positions where their tips 85 are locatedwell above the surface 90 so as to be able to support the in-processsubstrate above and out of thermal contact with heated platen 18. Thedegree to which lift pin 84 movement must physically separate thesubstrate from surface 90 is dependent on the cooling needs and fluidflow characteristics of the internal processing chamber 14. In short,lift pin mechanisms 84 can be raised to cause an in-process substrate tobe physically and thermally separated from heated platen 18 and can belowered to bring the substrate into thermal contact with surface 90.

[0089] To accomplish movement of lift pin mechanisms 84 simultaneously,each lift pin 84 is preferably connected to a common element, such as aplate or ring (not shown) so that a drive mechanism 92 can actuate justthe single element to simultaneously raise or lower all lift pinmechanisms 84 together. The drive mechanism 92 can comprise any known ordeveloped mechanism capable of linear movement, such as a lead screwmechanism driven by a stepper motor. It is further preferable that eachlift pin 84 further include an internal passage 94 that can beconventionally connected with a vacuum line or system so as to drawvacuum through tips 85 for holding the substrate against the tips 85.

[0090] Temperature sensing mechanism 93 is coupled to heated platen 18to monitor heated platen temperature. Temperature sensing substrateenters chamber 14 through aperture 95 and is held in place by collar 97.O-ring 99 helps to provide a good seal at this opening. Temperaturesensing mechanism 93 may be any conventional substrate such as an RTD orthermocouple. Temperature sensing mechanism 93 is connected to a controlcircuit (not shown) so as to allow heated platen temperature to bemonitored and controlled in a conventional manner. The control mechanismitself does not form a particular part of the subject application andcan be provided in any known or developed manner consistent with thebasic operation of controlling the heat generated based upon temperaturesensing information.

[0091] Lid 24 seals the top of station 10. Lid 24 preferably is formedfrom a double panel structure in which generally circular panel 98 isattached in spaced apart fashion to cover plate 100. The spacing betweenpanel 98 and cover plate 100 is maintained by peripheral wall flange 102and inner, annular wall flange 104 positioned generally concentricallyand radially inward from wall flange 102. To help strengthen lid 24,cover plate 100 is further supported upon a plurality of spaced apartposts 106. Radial reinforcing ribs 108 extending between posts 106 andwall flange 104 further help to strengthen lid 24. Cover plate 100 issecured in place using a plurality of fasteners 110. Gasket 112 (notshown in FIG. 2) helps to form a good seal between cover plate 100 andthe other portions of lid 24 to which it is attached.

[0092] The structure of lid 24 thus defines an outer, annular plenum 114and an inner plenum 116. Outer plenum 114 is in fluid communication withprocessing chamber 14 through a plurality of ports 118 distributeduniformly around annular portion 122 of panel 98 in a preferred annulararray. Inner plenum 116 is in fluid communication with processingchamber through a plurality of ports 120 distributed about inner portion124 of panel 98. Each of plenums 114 and 116 independently provides apathway by which process gases can be independently or collectivelyintroduced into process chamber 14 in a controlled, showerhead fashion.To this end, one or more sources (not shown) of process gases may beindependently coupled to inner and outer plenums 114 and 116 viaconventional plumbing.

[0093] Advantageously, the combination curing/in situ cooling station 10shown in FIGS. 1 through 4 may be used to first cure films containing acurable dielectric precursor to form a dielectric film, and secondly tocool the cured film in situ with a gas before the substrate bearing thecured film is removed from the station 10. In situ cooling of the filmis important to minimize thermo-oxidative decomposition of the film. Apreferred mode of operation to accomplish curing and in situ coolinginvolves a loading stage, a gas purging stage, a curing stage, a coolingstage, and an unloading stage. In the loading stage, door 28 is openedto allow a substrate to be placed into process chamber 14. At this time,an annular curtain of one or more non-oxidizing gas(es) flows downwardinto chamber 14 through the outer plenum 108 of lid 24 to help isolateprocess chamber 14 from the ambient. Optionally, one or morenon-oxidizing gas(es) may also flow into chamber 14 through inner plenum110 during the loading stage, but this is not required. The substratebearing a baked coating containing a dried or substantially drieddielectric precursor is placed onto raised lift pin mechanisms 84,generally positioning the substrate substantially out of thermal contactwith heated platen 18. Door 28 is then closed to environmentally sealprocess chamber 14.

[0094] Throughout this and any stage of the operation, the non-oxidizinggas(es) flowing through outer plenum 114 and/or inner plenum 116, as thecase may be, preferably is/are independently selected from nitrogen,helium, argon, a forming gas comprising N₂ and H₂, combinations ofthese, and the like. Nitrogen presently is preferred. The gas or gasesmay be supplied at any temperature within a wide range. A representativetemperature is from more than about 0° C. to about 300° C., preferablyabout 15° C. to about 250° C., and more preferably at about ambienttemperature, e.g., about 20° C. to 25° C. Throughout the entire curingand in situ cooling operation, each flow of gas(es) through the innerand outer plenums 116 and 114 is supplied independently at a respectiveflow rate ranging from about 0.5 ft³/hr to 100 ft³/hr. A preferred flowrate for the outer gas flow is 40 ft³/hr, and a preferred flow rate forthe inner gas flow is about 50 ft³/hr, or vice-versa.

[0095] The next stage of operation is the gas purging stage. In thisstage, process chamber 14 is purged with a flow of one or morenonoxidizing gases in order to controllably establish and maintain ananaerobic processing environment with a controlled, reduced amount ofoxygen. The ability to control the oxygen level during the curingprocess is important, because many dielectric precursors as well as theresultant dielectric films are susceptible to thermal oxidation atelevated temperatures in the presence of oxygen. For many dielectricmaterials, especially dielectric materials containing organiccomponents, thermal oxidation becomes a risk even in ordinary air attemperatures in the range of from about 325° C. to about 375° C.,depending upon the particular material. Because dielectric precursorsare generally cured at temperatures well above this temperature regime,the substrates bearing these materials are desirably maintained in ananaerobic environment so long as the substrates are hot enough forthermal oxidation to be an undue risk. Accordingly, when the dielectricmaterial being used is organic, the oxygen content is desirably as lowas possible. Taking practical considerations into account, the oxygencontent during anaerobic processing is preferably up to 200 ppm, morepreferably 1 to 200 ppm, most preferably 5 to 20 ppm.

[0096] A somewhat higher oxygen level may be desired for other kinds ofdielectric materials in order to help ensure that curing proceeds in apreferential direction. For example, inorganic dielectric precursorsbenefit from having oxygen present in order to help ensure that curingoccurs with minimal side reactions. Accordingly, when the dielectricmaterials being used are inorganic or inorganic-organic, process chamber14 is purged under conditions effective to establish an anaerobicprocessing environment containing 100 ppm to 2000 ppm, preferably about200 ppm oxygen.

[0097] In addition to establishing a controlled level of oxygen inchamber 14, a vacuum may be established in processing chamber 14 in thispurging stage, if desired, to enhance the dielectric properties of theresultant cured film. Establishing such a vacuum is particularlydesirable in those applications in which a porous, dielectric film is tobe formed. Some kinds of porous dielectric films are formed frommaterials that not only include a dielectric precursor, but also includeone or more materials (“porogens”) that tend to volatilize under thecuring conditions and outgas to create porosity during the cure. Avacuum is used to facilitate such outgassing. The level of vacuum to beestablished will vary depending upon the nature of the dielectricmaterial and is typically specified by the material manufacturer. Assuggested guidelines, the capability of establishing a vacuum in therange from about 1 torr up to about ambient would be suitable. Apreferred vacuum level presently is about 20 torr.

[0098] During the nitrogen purge, a non-oxidizing gas preferablypurgingly flows into chamber 14 through inner plenum 116 of lid 24. Anoptional flow of non-oxidizing gas through outer plenum 114 may also beused, but is not required. With a flow of about 50 ft³/hr through theinner plenum 116, purging occurs for a period of about 10 seconds toabout 5 minutes, preferably about 15 to 60 seconds.

[0099] After the oxygen content in the processing chamber is at thedesired level, the curing stage of the operation stage takes place. Liftpin mechanisms 84 supporting the substrate are lowered to place thesubstrate into thermal contact with heated platen 18. In the practice ofthe present invention, thermal contact may involve actual physicalcontact between the substrate and heated platen 18, but actual physicalcontact is not required. Effective heating can be achieved bypositioning the substrate in close proximity to heated platen 18, e.g.,at a distance of 6 mil to 50 mil. Indeed, such a gap is preferred insome applications, because actual physical contact can contaminate theback side of the substrate. As a consequence, the substrate is heatedunder conditions effective to cure the dielectric precursor and form acured dielectric film on the substrate. The curing temperature will varydepending upon the type of dielectric precursor being cured. For thecommercially available dielectric precursors, the heated platen 18 istypically maintained at a temperature within the range from about 350°C. to about 450° C. The length of time at which the substrate is curedwill also vary depending upon the kind of dielectric precursor beingcured. Generally, station 10 of the present invention is capable ofachieving very rapid curing, and curing periods of no more than tenminutes, preferably 1 to 3 minutes would be sufficient.

[0100] After the curing stage is completed, the cooling stage occurs.Because dielectric films are susceptible to thermal oxidation if exposedto the ambient while at elevated temperatures, the substrate isadvantageously cooled in situ to a suitably low threshold temperaturebefore being removed from station 10. This threshold temperature isgenerally in the range from 200° C. to about 325° C., preferably about250° C. Lower temperatures could be used, if desired, but such apractice will increase cycle time. Higher temperatures could also beused if desired, but with an increased risk of subjecting the cureddielectric film to thermal oxidation.

[0101] In the practice of the present invention, such in situ cooling isaccomplished by raising lift pin mechanism 84 to thermally decouple thesubstrate from the heated platen 18. In practice, the physicalseparation between heated platen 18 and the raised substrate isgenerally about 100 mil to 600 mil, preferably about 530 mil. In situcooling is then accomplished by causing a flow of gas through innerplenum 116 to coolingly contact the substrate while the substrateremains inside station 10. An optional flow of gas may also enter thechamber through outer plenum 114 if desired, but this is not required.Cooling is relatively rapid and can be completed in about 1 to 2minutes.

[0102] After the substrate is cooled to the desired target temperature,the substrate is removed from station 10 in the unloading stage of theoperation. With the cured and cooled substrate supported upon raisedlift pin mechanisms 84, a curtain flow of gas through outer plenum 116is established (if not already flowing) to help form a barrier betweenchamber 14 and the ambient. An optional flow of gas through inner plenum116 may be maintained as well, but this is not required. With thecurtain flow established, door 28 is opened, and the substrate may beremoved from chamber 14 by a suitable handler, e.g., a robot or thelike.

[0103]FIG. 5 shows one embodiment of an approach of the presentinvention in which the oxygen level in combination cure/in situ coolingstation 10 of FIGS. 1 through 4 is controllable. FIG. 5 shows station 10in simplified form as including process chamber 14 in which in-processmicroelectronic substrate 16 is supported upon lift pins 84 above heatedplaten 18. Door 28 opens and closes to allow loading and unloading toand from process chamber 14. To carry out in situ cooling in accordancewith the present invention, source 170 of cooling gas is fluidly coupledto chamber 14 via supply line 172. The flow of cooling gas flowingthrough line 172 is controlled via valves 174 and 176. Oxygen containinggas (such as ambient air) from source 178 is fluidly coupled to line 172via line 180. Valve 182 controls the amount of oxygen containing gascombined with cooling gas so that the level of oxygen in cooling gasentering chamber 14 can be controllably maintained at desired processinglevel(s) during curing and in situ cooling. Valve 176 controls the flowof oxygen containing cooling gas into chamber 14. One or more additionalprocess gases may also be fluidly coupled to chamber 14. For purposes ofillustration, a source 184 of conventional forming gas containingnitrogen and hydrogen is fluidly coupled to chamber 14 via supply line186. Valve 188 controls the flow of the forming gas. Process gases areexhausted from chamber 14 via exhaust line 190. Exhaust line 190 isoperationally coupled to vacuum pump 192 to allow chamber 14 to beplaced under vacuum if desired. Valve 193 controls the flow of exhaustgases from process chamber 14.

[0104] In order to monitor and control oxygen level in process chamber14, a portion of the exhaust gases is drawn off through line 194 tooxygen sensor 196. Valve 198 controls this flow. Oxygen sensor 196 canbe any suitable sensor capable of accurately measuring oxygen levels ina range at least including about 5 ppm to about 500 ppm. A variety ofsuch sensors are commercially available and any could be used. Onespecific example of an oxygen sensor found to be suitable in thepractice of the present invention is commercially available under thetrade designation Oxygen Analyzer #60-0329 from Illinois Instruments,Inc.

[0105] Oxygen sensor 196 generates an output signal 200 indicative ofthe oxygen level in the exhaust gases. The output signal 200 istransmitted to controller 202. Using conventional control methodology,controller 202 generates a control signal 204 indicative of the degreeto which the oxygen content in the exhaust gases deviates from thedesired level. An appropriate control signal 204 is sent to valve 182 toreduce the flow of oxygen containing gas into line 172 if the measuredoxygen level is too high or to increase the flow of oxygen containinggas into line 172 if the measured oxygen level is too low.

[0106]FIG. 5 illustrates a feedback approach for controlling the oxygenlevel in process chamber 14. Of course, any other suitable controlmethodology could be used. For example, feedforward control could beimplemented by measuring the oxygen level in the gas entering processchamber 14 and then using the measurement to derive an appropriatecontrol signal to send to valve 182. As another option, oxygen levels inboth the inlet and exhaust gases could be monitored as the basis for acombination feedback and feedforward control methodology.

[0107] The combination cure/in situ cooling stations of the presentinvention may advantageously be incorporated into cluster tools in whichcoating, baking, curing, and cooling all occur in one integrated system.A particularly preferred, integrated cluster tool incorporating thecuring and in situ cooling capabilities of the present invention iscommercially available from FSI International, Inc., Fremont, Calif.,USA, under the trade designation CALYPSO™. This cluster tool isadvantageously used to form low-k spin on dielectric films onmicroelectronic substrates. The cluster tool integrates spin-coating,baking, curing, in situ cooling, and chilling operations in a singleplatform capable of high volume production. More than one of each kindof station may be included to further increase productivity withoutincreasing footprint. Dielectric films made using this tool tend to havelower refractive indices and dielectric constants as compared tootherwise identical films that are furnace processed.

[0108] Due to the integrated curing and in situ cooling capabilities inparticular, the need to have a separate furnace on hand for curing iseliminated, further minimizing the total cleanroom floorspace needed toform low-k spin on dielectric films. In short, the tool provides highproductivity while also using valuable cleanroom floorspace veryefficiently. Throughput of up to about 100 substrates per hour areeasily achieved by this tool, which only occupies a footprint of about64 ft². The integration of coating, baking, curing, and cooling into onetool not only significantly enhances low-k spin on dielectric filmquality and uniformity, but also reduces device contamination. Curingand in situ cooling are preferably accomplished in a single, combinationcuring/in situ cooling station of the type shown in FIGS. 1 through 4herein or in Assignee's co-pending application identified above.

[0109] The CALYPSO™ cluster tool is extremely versatile in terms ofprocessing capabilities. Substrates may be individually processed,sequentially processed, or parallel processed using the same processrecipe or custom process recipes for any one or more of the substratesbeing processed. The tool can easily handle substrates of differentsizes. For example, by merely switching the robot end effector on thecentrally located robot and the spin coating shield in the coatingstation(s), and by then selecting the appropriate process recipe in thePC-based control system, the tool can be converted from 200 mmprocessing capability to 300 mm processing capability, and vice versa.The need to have separate machines for processing 200 mm and 300 mmwafers, respectively, is thus eliminated. This is still yet another wayin which the tool saves valuable cleanroom floorspace. The tool also iscapable of forming dielectric films, including porous dielectric films,from a wide range of low-k spin on dielectric precursors including butnot limited to the commercially available POLY ELK, LKD, HSG, porousSILK 2, ISP, and porous FLARE, dielectric precursor materials.

[0110] The CALYPSO™ cluster tool also prepares lower k dielectric filmsas compared to conventional furnace-based processes. Dielectric filmsproduced using the principles of the present invention as practiced onthis tool also have lower refractive index and show tremendous thicknessuniformity from wafer to wafer. For example, when forming dielectricfilms from the FLARE material, wafer to wafer thickness uniformity of0.2% or better (one sigma) are easily achieved. In the practice of thepresent invention, thickness uniformity is determined from 49 thicknessdata points measured using a NANOMETRICS tool to make the measurements.As compared to otherwise identical furnace-based processes, dielectricfilms of the present invention also tend to have better thermalstability. The high quality of the dielectric films allows resultantfilms to be integrated with multilevel aluminum (subtractive metalprocessing) and/or copper (e.g., dual damascene processing) for ULSIapplications.

[0111] A representative embodiment of the versatile CALYPSO™ clustertool 300 is schematically shown in FIG. 6, in which tool 300 is shown inone illustrative production configuration. Cluster tool 300 generallyincludes a plurality of modules 302, 303, 304, 305, 306, 307, and 308operationally positioned around central robot 310. Advantageously, eachof modules 302, 303, 304, 305, 306, 307, and 308 is a self-containedmodule complete with frame, skins, electronics, control hardware, andprocessor and facility connections. The facility connections areindependently coupled to a facility platform centrally located belowrobot 310. The modularity allows individual modules to be easily removedfor service, upgrade, replacement, or the like.

[0112] Wall 312 optionally includes one or more access ports, e.g., adoor or panel or the like, to allow access into cluster tool 300 forservice and maintenance. Wall 312 also may include one or moretransparent panels to allow visual inspection of the interior region 316of cluster tool 300.

[0113] Robot 310 includes base 322, jointed arm 324 attached to base 322at joint 326, and end effector 328 releasably attached to distal end 330of arm 324. End effector 328 releasably grips a wafer 344 beingprocessed. In some embodiments, an end effector to be used on arm 324 isdesigned to be able to grab and release devices of a particular size orsize range. In such embodiments, end effectors are swapped in order toswitch from 200 mm processing to 300 mm processing, or vice versa. Inother embodiments, a so-called universal end effector may be used thatis capable of gripping and releasing objects of various sizes. In suchembodiments, the same end effector can be used to handle both 200 mm and300 mm wafers without the need for swapping the end effector for anotherone. Advantageously, robot 310 can reach any station in the cluster tool300. This full, operational range eliminates the need for additionaland/or secondary robots, although one or more of such additional robotscould be incorporated into cluster tool 300 if desired.

[0114] An integrated selection of modular processing stations isarranged within operational reach of robot 310 in the various modules302, 303, 304, 305, 306, 307, and 308. The kind of stations, the numberof each kind of station, and the placement of each kind of station inone or more of modules 302, 303, 304, 305, 306, 307, and 308 will dependupon factors such as the desired throughput, the process recipes to beused, the available utilities, the type of device being fabricated, andthe like. One or more stations may be placed in each module, and thestations positioned in a particular module may be the same or different.For purposes of illustration, one suitable arrangement of stations incluster tool 300 is shown in FIG. 6.

[0115] Specifically, one or more input/output (I/O) stations aremodularly inserted into module 302. One or more cassettes 342 holdingone or more wafers 344 may be loaded into I/O stations 340 through adoor (not shown) or pod (not shown). Robot 310 can then access wafers344 held in cassette 342, typically one wafer at a time, through a door(not shown) on the interior face 350 of cabinet 302. For purposes ofillustration, three I/O stations are shown.

[0116] One or more spin-coating stations are incorporated into module303. For production 2 to 3 spin coating stations are preferred. Module304 may be used to store reservoirs 349 (four reservoirs 349 shown forpurposes of illustration) of one or more process chemicals used in thevarious stations. For example, one reservoir 349 may be used forsolvent, and the others may be used to hold dielectric precursor fluids.These reservoirs 349 are fluidly coupled to one or more of thespin-coating stations by suitable plumbing (not shown). One or more bakestations are incorporated into module 306. The bake stations mayincorporate not just a bake plate but also an intrastation chill plateto accomplish chilling after a baking operation. A preferred embodimentof module 306 includes six bake stations. Module 306 also includes achill station. One or more combination curing/in situ cooling stationsof the present invention are incorporated into module 307. A preferredembodiment of module 307 includes six combination of these curing/insitu cooling stations. Cabinet 308 may incorporate central controls foroperating tool 300.

[0117] An alternative embodiment of the CALYPSO™ cluster tool 300′ isshown in FIG. 7, in which the configuration of tool 300′ is suitable forresearch and development applications. Cluster tool 300′ generallyincludes a plurality of modules 302′, 303′, 304′, 305′, 306′, 307′, and308′ operationally positioned around a central robot 310′. Wall 312′helps to isolate interior region 316′. Module 302′ houses a pair of I/O(FOUP) stations. Module 303′ houses a single spin coating station and ispositioned next to module 304′, which houses spin coating chemicals,e.g., a solvent and three different spin coatable fluids in oneembodiment. In the current CALYPSO™ design, up to two spin coatingstations may be incorporated into module 303′. If more spin coatingstations are desired, one or more additional modules may be added totool 300′. Module 305′ is presently blank and may later house additionalprocessing stations for future expansion. Module 306′ houses three bakestations and one chill station. Up to four more bake stations may beadded to module 306′. Module 307′ houses a pair of curing/in situcooling stations and may hold up to four more of these. Controls arehoused in module 308′.

[0118] A preferred mode of operation of cluster tools of the presentinvention will now be described in connection with FIG. 6 and the flowchart 400 shown in FIG. 8. In step 402, robot 310 withdraws a wafer 344from I/O station 340. Prior to withdrawing the wafer, at that time, orafterwards, in step 404, a process recipe is selected for the wafer. Theremainder of the process steps in flowchart 400 will be carried out inaccordance with such recipe selection. In step 406, the robot 310transfers the wafer to a spin-coating station. At that station inaccordance with step 408, a spin-coatable composition comprising acurable dielectric precursor and solvent is dispensed onto the wafer asthe wafer is rotated. This may be accomplished in one or more coatingsteps, depending on the materials being used. Spin coating forms arelatively thin, uniform, fluid coating on the wafer comprising thedielectric precursor and the solvent.

[0119] In a typical spin coating operation, the composition is dispensedonto the center of a spinning substrate. For example, the spin coatingstation on the CALYPSO cluster tool includes three nozzles in someapplications for dispensing up to 3 different chemicals onto the same ordifferent substrates, usually being dispersed in succession. This3-nozzle structure is useful for coating the SILK material onto asubstrate in a 3-step process of priming, pre-wetting with a solvent,and top coating as recommended by the manufacturer. In each instance,the nozzle being used is translated proximal to the center axis of therotating substrate in order to carry out the dispense.

[0120] Center dispense is a very suitable technique, but somealternative approaches may be used that reduce the volume of dispensedmaterial required to effectively coat the spinning substrate. One suchtechnique involves first pre-wetting the substrate with solvent afterwhich a relatively reduced volume of the dielectric composition isdispensed. Pre-wetting can reduce the needed amount of dielectriccomposition. An alternative technique involves dispensing the dielectriccomposition as the nozzle translates radially either outward or inwardrelative to the spinning substrate. Radial dispensing may also be usedin combination with a pre-wetting step. As compared to a centerdispense, radial dispensing can reduce the needed volume of dielectriccomposition by as much as 25%.

[0121] After spin coating, edge bead removal (EBR) and/or backside rinse(BSR) treatments may optionally occur. The EBR treatment may occur usingany suitable technique. A preferred EBR treatment occurs by cutting theedge bead on the coated wafer with a jet of solvent while the coatedwafer spins at a suitable speed. When cutting the edge bead in thismanner, some of the dielectric material may move to the backside of thewafer. Accordingly, it is preferred to follow the EBR treatment with aBSR treatment in which the debris on the backside is rinsed off with asolvent while the wafer spins.

[0122] Preferably, the EBR and/or BSR treatments occur only after thecoated dielectric precursor material has dried to a suitable degree.According to one approach, the coated wafer may be allowed to dry in thespin coating station. However, depending upon the size of the wafer andthe thickness of the film, such drying may require from about 1 minuteto about 5 minutes. This is particularly the case for a 1 micrometer to2 micrometer thick coating on a 300 mm wafer. To reduce this dryingtime, it can be much faster to transfer the coated wafer to a bakestation, bake the coated wafer for a few seconds, and then transfer thecoated wafer back to a spin coating station at which the EBR and/or BSRtreatments occur.

[0123] After spin coating and any optional EBR and/or BSR treatments, inaccordance with step 410, robot 310 transfers the coated wafer to a bakestation. At the bake station, in accordance with step 412, the wafer isbaked to remove all or a portion of the solvent so as to prepare thecoated film to be cured in a subsequent curing step. Baking generallyoccurs within a relatively low temperature regime in which thetemperature is below the recommended cure temperature and in which therisk of thermal oxidation is at least substantially avoided. Thetemperature is desirably high enough, however, to allow the solvent tobe removed in a reasonable amount of time. Typically, during baking,there is some advancement of the cure of the dielectric material to theso-called B-stage of polymerization. A typical temperature for baking isin the range from about 100° C. to 350° C., preferably about 200° C. toabout 325° C. depending upon the material.

[0124] It has now been discovered that the presence of residual solventremaining in the baked coating can have a dramatic impact upon thequality and uniformity of the resultant cured films. Specifically, ifall or substantially all (i.e., if the baked coating includes 0.1 weightpercent or less of residual solvent based upon the total weight of thebaked coating) is removed from the coating during the baking, thequality of the resultant cured dielectric film may vary too much fromdevice to device. Additionally, the resultant cured material itself maybe different than what would have been expected based upon the startingprecursor material. In contrast, if an amount of residual solventremains in the coating after baking and is present at the onset ofcuring, the properties of the resultant cured films are much moreuniform. The nature of the cured material itself also correlates betterto the starting precursor material. Accordingly, it is preferred toremove all but a relatively small amount of residual solvent in thebaking step. Therefore, baked coatings of the present inventionpreferably include at least about 0.1 weight percent to about 5 weightpercent, more preferably 0.5 to 2 weight percent, and most preferablyabout 1 weight percent of residual solvent based upon the total weightof the baked coating.

[0125] With baking complete, the wafer is chilled and then robot 310transfers the baked wafer from the bake station to a combination cure/insitu cooling station in accordance with step 414. In step 416, the waferis loaded into the station, the station is purged with N₂ or the like toreduce the O₂ to the desired level, the baked coating on the wafer iscured, the cured film is then cooled in situ with a cooling gas, andthen the cooled wafer is unloaded from station 362. In accordance withstep 418, the robot then transfers the wafer to a chill station. There,the wafer is chilled to a desired final temperature in step 420. Robot310 then transfers the wafer back to an I/O station in step 422 tocomplete the process for that wafer. The process shown in flowchart 400may be repeated for a succession of one or more additional wafers usingthe same and/or different process recipes. After the film is formed, itmay thereafter be patterned to form an insulating element or the likeusing any suitable technique.

[0126] In situ cooling in the context of an integrated processing systemof the present invention, such as cluster tool 300, provides numerousbenefits. First, as described above, in situ cooling helps to protectthe wafer from thermal oxidation when the wafer is removed from station362. This significantly enhances the quality of the resultant dielectricfilm. Second, robot handling leaves less of an end effector signatureupon a cooled wafer, as compared to circumstances when a robot handles ahotter wafer. This, too, enhances the quality of the resultantdielectric film.

[0127] Third, with reference to FIG. 8, in situ cooling eliminates anyvariation in intrastation time period t₃ between curing and cooling sothat every processed wafer experiences the very same process during thecure and cooling operation. This consistent timing capability not onlyenhances the quality of the resultant dielectric film, but alsodramatically improves the wafer-to-wafer uniformity of cured low-k spinon dielectric films. In contrast, if there is too much variation in thetime period t₃ between curing and cooling, as is the case for wafersbatch cured in a furnace, uniformity is much worse and a unique processsignature can be discerned on individual wafers.

[0128] In fact, this t₃ consistency, preferably in combination withcontrolling and preferably maintaining consistent interstation transfertimes t₁ and t₂, offers tremendous flexibility and uniformity inprocessing microelectronic substrates. By making these time periodsconsistent between the bake, coat, cure, and cool operations, one can beassured that following a particular process recipe will provide adielectric film of a particular quality with very little variation fromsubstrate to substrate.

[0129] For example, a plurality of wafers can be sequentially processedthrough the system in which each wafer is subjected to the same coating,baking, curing, cooling, and optionally chilling recipe (including thesame t₁, t₂, and t₃) to provide substrates bearing low-k dielectric,thin films with excellent wafer-to-wafer thickness uniformity. Moreover,a plurality of wafers can be sequentially processed through the systemin any order using two or more recipes, and the groups of wafersprocessed according to a particular recipe will be virtuallyindistinguishable from each other. This flexibility also allowssubstrates to be custom processed on the fly. Such uniformity cannot beachieved as easily when coating, baking, curing, and cooling of spin ondielectric compositions are not integrated into a single, integratedsystem in which t₁, t₂, and/or t₃ are not as easily controlled orcontrollable.

[0130] Moreover, because cluster tool 300 may include multiple coating,baking, curing/cooling, and chilling stations, respectively, a pluralityof wafers may be parallel processed in accordance with one or morerecipes. Significantly, and due at least in part to the interstationcontrol over time periods t₁ and t₂ and the intrastation control of thetime period t₃ (if any, because one can transition from curing tocooling with essentially no delay such that t₃ is zero for practicalpurposes), uniformity of films prepared according to the same processrecipe is exceptional, even though any particular substrate may havebeen processed on one or more different stations than another substrate.

[0131] Accordingly, when subjecting a plurality of substrates to aparticular coating, baking, and curing/cooling recipe, it is preferredthat at least one of t₁, t₂, and/or t₃ is/are controlled for each ofsuch devices. More preferably, two or more of these time periods arecontrolled so as to be consistent from substrate to substrate, and mostpreferably all three of these time periods are controlled and aresubstantially the same, respectively for the substrates. As used withrespect to these time periods, “substantially the same” means that anysuch time period for a particular substrate varies by no more than 25%,preferably no more than 10%, and most preferably no more than about 1%with respect to the corresponding time period for any other substratebeing processed in accordance with such recipe.

[0132] Parallel processing of wafers is schematically illustrated inFIG. 9 by flowchart 500 for a illustrative system that includes a singleI/O station, a trio of spin coating stations, a trio of baking stations,a trio of cure/cooling stations, and a trio of chill stations. Flowchart500 shows the process flow paths 501 a, 501 b, and 501 c for threerepresentative in-process wafers. As schematically shown by theexemplary process flow paths 501 a, 501 b, and 501 c, each wafer iswithdrawn from the I/O station in step 502 and is then correlated with aparticular recipe, which may be the same or different than the recipesfor the other in-process wafers, in step 504. Next, each wafer issubjected to a respective sequence of a coating step 506, a baking step508, a curing/cooling step 510, a chilling step 512, and a step 514 inwhich the device is returned to the I/O station. The process can then berepeated for more wafers as desired. If a single recipe is followed forall the wafers, the resultant dielectric films on each wafer will bevirtually identical even though any one particular film may have beenprocessed in one or more different stations than other films. If morethan one recipe is followed, the resultant films produced according to aparticular recipe will be virtually identical to each other.

[0133] For maximum throughput, the three wafers are parallel processed.In the practice of the present invention, this does not necessarily meanthat a particular trio of wafers is processed through the same steps intandem, but rather that at least a portion of the coating, baking,and/or curing/cooling operations for one wafer will occur while at leasta portion of the coating, baking, and/or curing/cooling operations areoccurring for one or both of the other wafers. Further, more than onewafer may be processed in accordance with a particular flow path 501 a,501 b, 501 c, or the like, at any one time. For example, if one wafer onflow path 501 a is at the chilling step 512, one or more other wafersmay be following the same flow path at one or more of the otherstations. In other words, as soon as an in-process wafer leaves astation and it is unoccupied, another in-process wafer can take itsplace to maximize throughput.

[0134] The present invention will now be further described in connectionwith the following illustrative examples.

EXAMPLE 1

[0135] Low-k spin-on dielectric thin films were formed on a batch of 25silicon wafers using the CALYPSO® tool cluster. A cassette storing thewafers was placed into the I/O module of the cluster. Each wafer wasprocessed using an identical, predetermined, sequential processcontrolled through software packaged with the tool.

[0136] Each wafer was first transported by the central robot from theI/O module to a coating station where the wafer was coated with anadhesion promoter (AP 4000 available from the Dow Chemical Co.). The AP4000 adhesion promoter (1 ml) was dispensed onto the center of eachwafer while the water spun at 2500 rpm. After this dispense, the centralrobot transferred the wafer from the coating module to a bake station.The AP 4000 film on the wafer was baked at 200° C. for 60 seconds. Thewafer was then transferred by the central robot from the bake station toa chill station for processing at 20° C. for 20 sec. The central robotthen moved the chilled wafer back to the coat station. In the coatstation, a low-k SILK dielectric precursor (Dow Chemical Co.) wasdispensed (1.8 ml to 3 ml) onto the center of the wafer using dynamicdispense at a dispense speed of 1500 rpm. After the dispense, the waferspin was ramped up to 3600 rpm for 45 seconds. Edge bead removal (EBR)then was performed at 1500 rpm using cyclohexanone at 2 mm from the edgeof the wafer. A BSR treatment was also performed using cyclohexanone ata spin speed of 1500 rpm. The wafer was allowed to continue to spin at3000 rpm for another 10 seconds.

[0137] The central robot then moved the wafer to a first INSTACURE™station to carry out a baking step at 325° C. for 60 seconds. The waferswere then moved to another INSTACURE™ station with a heated platenmaintained at 450° C. The thin film of coated SILK material was cured inthe INSTACURE™ station at 450° C. for 180 seconds with the oxygen levelmaintained at <20 ppm. The cured wafers were cooled in the INSTACURE™station using nitrogen by lifting the wafers from the heated platenusing the pins to support the wafer while maintaining the anaerobicconditions. Once the wafers were cooled to below 325° C., the waferswere then transferred to a chill plate maintained at 20° C. for 20 sec.The processed wafer was then returned to its cassette.

[0138] During loading of the wafer into the INSTACURE™ station, nitrogenflowed through the outer plenum of the station at 55 standard ft³/hr(SCFH) as the wafer was placed on the lift pinspins. After the doorclosure, when the wafer was still supported on the pins, the nitrogenflowed through both inner and outer plenums of the lid at 55 SCFH and 45SCFH, respectively. During the curing, nitrogen flowed through the innerplenum only at 45 SCFH. When the wafer was cooled on the pins, nitrogenflowed through the inner and outer plenums at 55 SCFH and 45 SCFH,respectively.

[0139] The thickness of the resultant SILK thin film on each wafer wasmeasured using the instrument commercially available from Nanometrics.The average thickness of was about 5000 angstroms with thicknessuniformity of ≦0.15% (1 sigma).

[0140] For comparison purposes, a batch of 25 wafers was processed insimilar manner, except that the comparison wafers were cured in afurnace (ex-situ) at 400° C. for 60 minutes and cooled ex situ. Variousproperties of both the wafers processed in the CALYPSO® tool and thecomparison wafers were measured. The wafers processed in the CALYPSO®tool showed improved lower average refractive index of 1.6089 ascompared to furnace cured film with an average refractive index of1.6206. This and other data are reported in the following Table 1: TABLE1 INSTACURE ™ Furnace Cured SILK Film Property (450° C. for 3 min) (400°C. for 60 min) Refractive Index (Rudolph) 1.6089 (633 nm) 1.6206 (633nm) Thickness Uniformity ≦0.15% (1 sigma) ≦0.25% (1 sigma) RefractiveIndex 1.904 (314 nm) 1.915 (314 nm) Refractive Index Uniformity 0.016 (1sigma) 0.02 (1 sigma) Thermal Stability Less out-gassing Moreout-gassing (TE-GC-Mass) Elastic Modulus (Gpa) 4.2 3.86

EXAMPLE 2

[0141] Low-k spin-on dielectric thin films were formed on a batch of 25silicon wafers using the CALYPSO® tool cluster. A cassette storing thewafers was placed into the I/O module of the cluster. Each wafer wasprocessed using an identical, predetermined, sequential processcontrolled through software packaged with the tool.

[0142] To carry out the process, a wafer was transferred by the robot tothe coat station. A low-k SILK (new version, no adhesion promoterneeded) dielectric precursor (Dow Chemical Co.) dielectric precursorsolution was dispensed (1.8 ml to 3 ml) onto the center of the waferusing dynamic dispense at a dispense speed of 1500 rpm. After thedispense, the wafer spin speed was ramped up to 3600 rpm for 45 seconds.Edge bead removal (EBR) then was performed at 1500 rpm usingcyclohexanone at 2 mm from the edge of the wafer. A BSR treatment wasalso performed using cyclohexanone at a spin speed of 1500 rpm. Thewafer was allowed to continue to spin at 3000 rpm for another 10seconds.

[0143] The central robot then moved the wafer to a first INSTACURE™station to carry out a baking step at 325° C. for 60 seconds. The waferswere then moved to another INSTACURE™ station with a preheated platenmaintained at 450° C. The thin film of coated SILK material was cured inthe INSTACURE™ station at 450° C. for 180 seconds with the oxygen levelmaintained at <20 ppm. The cured wafer was cooled in the INSTACURE™station using nitrogen to a temperature below 325° C. while maintainingthe anaerobic conditions. The wafer was then transferred to a chillplate maintained at 20° C. for 20 sec. The processed wafer was thenreturned to the cassette.

[0144] During loading, nitrogen flowed through the outer plenum at 55SCFH. After the door closure, when the wafer is still on the pins, thenitrogen flowed through both inner and outer plenums at 55 SCFH and 45SCFH, respectively. During the curing, the nitrogen flowed through theinner plenum only at 45 SCFH. When the wafer was cooled on the liftpins, nitrogen flowed through inner and outer plenums at 55 SCFH and 45SCFH, respectively.

[0145] The thickness of the SILK thin film on each wafer was measuredusing the instrument commercially available from Nanometrics. Theaverage thickness was about 5900 angstroms with thickness uniformity of<0.15% (1 sigma). The refractive index of the film at 314 nm was 1.907.

EXAMPLE 3

[0146] In a manner similar to Example 2,300 mm wafers were processed onthe CALYPSO™ cluster tool. However, the wafers were coated with the SILKlow-k dielectric percursor while each wafer spun at 1700 rpm.Additionally, the wafers were cooled in-situ to below 300° C. beforebeing chilled and transferred back to the cassette.

[0147] The average thickness of the resultant films was measured as10,000 angstroms with a uniformity of <0.25% (1 sigma). The averagerefractive index measured at 314 nm was found to be 1.904.

EXAMPLE 4

[0148] Low-k spin-on dielectric thin films were formed on a batch of 25silicon wafers using the CALYPSO® cluster tool. A cassette storing thewafers was placed into the I/O module of the tool. Each wafer wasprocessed using an identical, predetermined, sequential processcontrolled through software packaged with the tool.

[0149] To carry out the process, the central robot moved a wafer to thecoat station. A low-k FLARE dielectric precursor (Honeywell) wasdispensed (2.5 ml) onto the center of the wafer using dynamic dispenseat a dispense speed of 1500 rpm. After the dispense, the wafer spinspeed was ramped up to 3600 rpm for 40 seconds. Edge bead removal (EBR)then was performed at 1500 rpm using cyclohexanone at 2 mm from the edgeof the wafer. A BSR treatment was also performed using cyclohexanone ata spin speed of 1500 rpm. The wafer was allowed to continue to spin at3000 rpm for another 10 seconds.

[0150] The central robot then moved the wafers to a succession of bakestations maintained at 150° C., 200° C., 250° C., respectively. Thebaking was perfromed for 60 seconds at each temperature. The wafers werethen moved to an INSTACURE™ station with a preheated platen maintainedat 450° C. The thin film of coated FLARE material was cured in theINSTACURE™ station at 450° C. for 180 seconds with the oxygen levelmaintained at <20 ppm. The cured wafer was cooled in the INSTACURE™station using nitrogen to a temperature below 325° C. while maintainingthe anaerobic conditions. The wafer was then transferred to a chillplate maintained at 20° C. for 20 sec. The processed wafer was thenreturned to the cassette.

[0151] During the loading, the nitrogen flowed through the outer plenumat 55 SCFH. After the door closure, before the wafer was lowered intothermal contact with the heated platen, nitrogen flowed through bothinner and outer plenums at 55 SCFH and 45 SCFH, respectively. Duringcuring, nitrogen flowed through the inner plenum only at 55 SCFH. Duringcooling, nitrogen flowed through inner and outer plenums at 55 SCFH and45 SCFH, respectively.

[0152] The thickness of the FLARE thin film on each wafer was measuredusing the instrument commercially available from Nanometrics. Theaverage thickness was about 5990 angstroms with a thickness uniformityof ≦0.15% (1 sigma).

[0153] For comparison purposes, a batch of 25 wafers was processed insimilar manner, except that the comparison wafers were cured in afurnace (ex-situ) at 400° C. for 60 minutes and cooled ex situ. Variousproperties of the wafers processed in the CALYPSO® tool and thecomparison wafers were measured. The wafers processed in the CALYPSO®tool showed improved lower average refractive index of 1.6089 comparedto furnace cured film with an average refractive index of 1.6206. Thisand other data are reported in the following Table 2: TABLE 2 InstacuredFurnace Cured SILK Film Property (450° C. for 3 min) (420° C. for 60min) Refractive Index (Whoolam) 1.669 (633 nm) 1.68 (633 nm) ThicknessUniformity ≦0.15% (1 sigma) ≦0.20% (1 sigma) Thermal Stability Lessout-gassing More out-gassing (TE-GC-Mass) Elastic Modulus (Gpa) 5.775.33 Hardness (Gpa) 0.384 0.363

[0154] Other embodiments of this invention will be apparent to thoseskilled in the art upon consideration of this specification or frompractice of the invention disclosed herein. Various omissions,modifications, and changes to the principles and embodiments describedherein may be made by one skilled in the art without departing from thescope and spirit of the present invention which is indicated by thefollowing claims.

What is claimed is:
 1. A method of forming a cured, dielectriccomposition on a substrate, comprising the steps of: (a) coating acomposition comprising a thermally curable, dielectric precursor onto atleast a portion of the substrate; (b) causing the coated substrate to bepositioned in a process chamber; (c) while the coated substrate ispositioned in the process chamber: (i) thermally curing the dielectricprecursor to form the cured dielectric composition; and (ii) causing agas to coolingly contact the cured dielectric composition; and (d) aftersaid gas coolingly contacts the cured dielectric composition, removingthe coated substrate from the process chamber.
 2. The method of claim 1,wherein the dielectric precursor comprises an organic prepolymercomponent, and wherein at least a portion of said thermal curing occursunder anaerobic conditions.
 3. The method of claim 1, wherein thedielectric precursor comprises an organic prepolymer component, andwherein at least a portion of said thermal curing and gas cooling occurunder anaerobic conditions.
 4. The method of claim 3, wherein at leastsubstantially all of the thermal curing and cooling gas contact occurunder anaerobic conditions.
 5. The method of 2, wherein the anaerobicconditions comprise thermally processing the coated substrate in ananaerobic environment comprising no more than about 200 ppm oxygen. 6.The method of 4, wherein the anaerobic environment comprises no morethan about 200 ppm oxygen.
 7. The method of claim 1, wherein thedielectric precursor comprises an inorganic prepolymer component, andwherein at least a portion of said thermal curing and gas cooling occurunder aerobic conditions.
 8. The method of claim 1, wherein a side dooroperationally engages a portal through which a substrate to be processedis transferred to and from the process chamber.
 9. The method of claim1, wherein the coating step comprises spin coating the compositioncomprising the curable dielectric precursor onto the substrate.
 10. Themethod of claim 1, wherein said dielectric precursor has a curetemperature, the coated composition comprises a solvent, and thermalcuring occurs at a temperature at or above the cure temperature, andwherein the method further comprises the step of, after coating butprior to curing, causing the coated composition to be pre-baked at atemperature below the cure temperature in order to remove at least aportion of the solvent.
 11. The method of claim 10, wherein saidpre-baking occurs under conditions such that the coated compositioncomprises an amount of residual solvent.
 12. The method of claim 11,wherein said amount of residual solvent comprises from about 0.5 toabout 5 weight percent of solvent of the total solvent included in thecomposition at the time of coating.
 13. The method of claim 1, whereinat least a portion of the thermal curing step occurs under vaccuum. 14.A method of forming dielectric compositions on a plurality ofsubstrates, comprising the steps of: (a) coating a compositioncomprising a curable dielectric precursor onto a first substrate; (b)causing the coated substrate to be prebaked, said prebaking beinginitiated after a first time interval from the end of the coating step;(c) causing the coated substrate to be thermally cured, said thermalcuring being initiated after a second time interval from the end of thepre-baking step; (d) causing the thermally cured substrate to be cooled,said cooling being initiated after a third time interval from the end ofthe thermal curing step; and (e) repeating steps (a) through (d) for atleast one additional substrate, wherein the respective second timeintervals for each of the first coated substrate and the at least oneadditional coated substrate are substantially the same.
 15. The methodof claim 14, wherein the respective first time intervals for each of thefirst coated substrate and the at least one additional coated substrateare substantially the same.
 16. The method of claim 14, wherein therespective third time intervals for each of the first coated substrateand the at least one additional coated substrate are substantially thesame.
 17. The method of claim 16, wherein the respective first timeintervals for each of the first coated substrate and the at least oneadditional coated substrate are substantially the same.
 18. The methodof claim 14 wherein at least a portion of the cooling occurs by causinga gas to coolingly contact the thermally cured substrate, and whereinthe thermal curing and said cooling gas contact occur in the sameprocess chamber.
 19. The method of claim 14, wherein the dielectricprecursor comprises an organic prepolymer component, and wherein atleast a portion of said thermal curing occurs under anaerobicconditions.
 20. The method of claim 15, wherein the dielectric precursorcomprises an organic prepolymer component and wherein at least a portionof said thermal curing and said cooling gas contact occur underanaerobic conditions.
 21. The method of claim 18, wherein at leastsubstantially all of the thermal curing and cooling gas contact occurunder anaerobic conditions.
 22. The method of claim 14, wherein at leasta portion of the thermal curing step occurs under vaccuum.
 23. A methodof forming a cured, dielectric composition on a substrate, comprisingthe steps of: (a) coating a composition comprising a thermally curable,dielectric precursor and an amount of solvent such that the compositionhas a coatable viscosity onto at least a portion of the substrate; (b)pre-baking the coated substrate at a first, relatively low temperatureprofile under conditions such that at least a portion of the coateddielectric precursor is uncured and the coated composition comprises aresidual amount of solvent; (c) thermally curing the dielectricprecursor at a second, relatively high temperature profile underconditions such that at least substantially all of the dielectricprecursor is cured to form the dielectric composition; and (d) coolingthe cured dielectric composition.
 24. A method of forming a cured,dielectric composition on a substrate, comprising the steps of: (a)coating a composition comprising a thermally curable, dielectricprecursor onto at least a portion of the substrate; (b) causing thecoated substrate to be positioned in a process chamber; (c) while thecoated substrate is positioned in the process chamber: (i) thermallycuring the dielectric precursor to form the cured dielectriccomposition, wherein at least a portion of the thermal curing occursunder anaerobic conditions; and (ii) causing a gas to coolingly contactthe cured dielectric composition; and (d) after said gas coolinglycontacts the cured dielectric composition, removing the coated substratefrom the process chamber.
 25. A method of forming respective dielectriccompositions on a plurality of substrates, comprising the steps of: (a)causing a first composition comprising a first dielectric precursor tobe coated onto a first substrate; (b) causing the coated, firstsubstrate to be positioned in a processing chamber; (c) while the firstsubstrate is positioned in the processing chamber: (i) causing the firstsubstrate to be in thermal contact with a heat source under conditionseffective to thermally cure the first, coated substrate; and (ii)causing a gas to coolingly contact the thermally cured, first substrate;and (d) repeating steps (a) through (c) for a second substrate.
 26. Themethod of claim 25, wherein at least a portion of at least one of therepeated steps (a) through (c) occurs while at least a portion of atleast one of said steps (a) through (c) is carried out with respect tothe first substrate.
 27. The method of claim 25, wherein said coating,positioning, thermal curing, and cooling steps are carried out in acluster tool comprising at least one input/output module, at least onecoating module, and at least one combination cure/cool module.
 28. Themethod of claim 27, wherein the tool comprises at least two cure/coolmodules and at least a portion of the curing step for the firstsubstrate occurs while at least a portion of the curing step for thesecond substrate is occurring.
 29. The method of claim 27, wherein thetool comprises at least two cure/cool modules and at least a portion ofthe gas cooling step for the first substrate occurs while at least aportion of the gas cooling step for the second substrate is occurring.30. The method of claim 27, wherein the tool comprises at least twocure/cool modules and at least a portion of the gas cooling step for thefirst substrate occurs while at least a portion of the gas cooling stepfor the second substrate is occurring.
 31. The method of claim 25,wherein each of the first and second substrates are processed inparallel according to first and second process recipes, respectively,said first and second process recipes being different.
 32. The method ofclaim 29, wherein each of the first and second substrates are processedin parallel according to first and second process recipes, respectively,said first and second process recipes being substantially identical. 33.The method of claim 25, further comprising subjecting each of the firstand second coated substrates to respective pre-bake treatments, saidpre-bake treatments occurring prior to thermal curing.
 34. The method ofclaim 33, wherein thermal curing of the first coated substrate isinitiated after a first time interval from the end of the correspondingpre-bake treatment and thermal curing of the second coated substrate isinitiated after a second time interval from the corresponding pre-baketreatment, said first and second time intervals being substantiallyidentical.
 35. The method of claim 34, wherein each of the first andsecond substrates are processed sequentially according to first andsecond recipes, respectively, said first and second recipes beingsubstantially identical.
 36. The method of claim 34, wherein each of thefirst and second substrates are processed sequentially according tofirst and second recipes, respectively, said first and second recipesbeing different from each other.
 37. A method of forming respectivedielectric compositions on a plurality of substrates, comprising thesteps of: (a) providing first and second groups of substrates, each ofsaid groups comprising at least one substrate to be processed; (b) inaccordance with a first process recipe: (i) causing a first compositioncomprising a first dielectric precursor to be coated onto each substratein the first substrate group; (ii) causing each of the coated,substrates of the first group to be positioned in a processing chamber;(iii) while each of the substrates of the first group is positioned inthe processing chamber: causing each such coated substrate of the firstgroup to be in thermal contact with a heat source under conditionseffective to thermally cure such coated substrate; and causing a gas tocoolingly contact each of the thermally cured, first substrates; and (c)in accordance with a second process recipe different than the firstprocess recipe, repeating step (b) for each of the substrates in thesecond group.
 38. An apparatus for thermally processing amicroelectronic device precursor, comprising: a process chamber in whichthe precursor is positioned during processing; a heat source thermallycoupled to the process chamber in a manner such that the precursor maybe heated during processing; a source of a cooling gas in fluidcommunication with the process chamber such that the cooling gas may becaused to coolingly contact the precursor during processing; and acontrol system that controls the heat source and source of cooling gasin order to subject the precursor to a desired thermal processingprofile involving at least one heating step and at least one coolingstep during processing.
 39. The apparatus of claim 38, furthercomprising a transport mechanism operationally coupled to the precursorpositioned in the process chamber in a manner effective to transport theprecursor through a range of motion comprising a precursor heatingposition and a precursor cooling position.
 40. The apparatus of claim38, further comprising a portal positioned on the side of the apparatusthrough which the precursor is loaded into and withdrawn from theprocess chamber.
 41. The apparatus of claim 38, wherein said heat sourcecomprises a bake plate positioned in the process chamber and wherein theapparatus further comprises a hollow support member upon which thebakeplate is supported at least in part.
 42. A cluster tool, comprisingat least one combination heat/cool process station comprising: a processchamber in which the precursor is positioned during processing; a heatsource thermally coupled to the process chamber in a manner such thatthe precursor may be heated during processing; and a source of a coolinggas in fluid communication with the process chamber such that thecooling gas may be caused to coolingly contact the precursor duringprocessing.
 43. The cluster tool of claim 42, further comprising aninput/output station, a coating station, a pre-bake station, and a robotcomprising an operational range of motion that allows the robot tooperationally load and unload a workpiece from each of the stations. 44.The cluster tool of claim 43, further comprising at one additionalheat/cool process station.
 45. The cluster tool of claim 44, wherein theadditional heat/cool process station is positioned vertically above theother heat/cool process station.
 46. The cluster tool of claim 43,further comprising a central source of at least one utility, saidutility source being independently coupled to the combination heat/coolstations.
 47. The cluster tool of claim 44, further comprising at leastone pre-bake station.
 48. The cluster tool of claim 42, furthercomprising a dispense station that is operationally coupled to a sourceof a coatable composition comprising a dielectric precursor in a mannereffective to allow an amount of the coatable composition to be coatedonto a substrate.